Author Topic: Thorn Mercury 650b owner review  (Read 26228 times)

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #30 on: August 14, 2021, 09:31:32 AM »
Releavant addition: PH was quite right in another thread to recommend protecting the paint from wear under the control cables. I've used a plastic film once and perhaps still sold as Con-tact but now available under different names.

JohnR

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Re: Thorn Mercury 650b owner review
« Reply #31 on: August 14, 2021, 07:05:56 PM »
I'm also interested in generating an antidote for the misinformation that still comes up quite prominently when you Google Thorn or Rohloff. Apparently Thorn bikes are appallingly ugly, burdonsomely overweight, and stubbornly old fashioned, while the Rohloff feels like you're pedalling in treacle and its seals apply a drag brake that restricts your speed on downhills.

My reality with the Mercury opposes all that directly: the frame is beautifully shaped and finished and its proportions are very pleasing to my eye; the weight impost for steel is negligible; the design for a bike with this use-envelope leads the market; the Rohloff feels like you're pedalling in Teflon; and the Rohloff applies no restriction on your speed downhill or anywhere else. I hope Thorn gets around to ordeing more frames.
Perhaps Thorn bikes become overweight because it's so easy to attach things to them? As I noted in the weight thread, my Mercury is the better part of 10kg heavier than when I took it out of the box (I'm currently investigating diet options for the bike).

Perhaps the Rohloff hub is slightly less efficient than a derailleur system in optimum condition, but for how long does that condition continue unless the rider is a fanatic who diligently cleans the drivetrain after each ride? And, as you'll discover, the Rohloff hub, like a fine wine, improves with age. At 6,000 miles the Rohloff hub on my Mercury is shifting very sweetly. I hope that anyone thinking of buying a Rohloff hub will find and read this http://www.sjscycles.com/thornpdf/ThornLivingWithARohloff.pdf .

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #32 on: August 15, 2021, 12:58:10 AM »
The misinformation I'm talking about rarely came from owners or from this forum - just the usual internet chatter from uninformed people with an opinion to share. Someone had bought something at the Thorn shop one day and had picked up a Nomad and decided it could anchor a ship, for example, and offered that as a comment on Thorn bikes in general.

It's the usual story: people with something critical to say will take opportunities to say it, whereas people having a great experience will keep that to themselves.

Even on this forum, I'd read everything I could find about the Mercury more than once, and while people were obviously happy with their bikes, or mostly so, I remained hungry for more detail.

So in this thread I thought i'd supply that for others. It's good to hear that the hub wears in quite quickly, JohnR - especially since the shifting on mine is pretty smooth anyway. Remarkable really to have a major bicycle component that wears in over a very extended lifetime rather than wearing out. Even a fine wine improves only on the shelf - once uncorked its performance peaks fast then declines.

Andre Jute

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Re: Thorn Mercury 650b owner review
« Reply #33 on: August 15, 2021, 11:10:44 AM »
Moronic wrote:
Quote
I'm also interested in generating an antidote for the misinformation that still comes up quite prominently when you Google Thorn or Rohloff.

You're doing very well indeed, Moronic, and I say that as professional writer and popularizer since I was 13.

Quote
Remarkable really to have a major bicycle component that wears in over a very extended lifetime rather than wearing out.

My favorite bike mechanic, who owns several heavily-used Rohloff gearboxes, says, "A Shimano Nexus lies itself down to die just about the time a Rohloff is run in." Mean time between failures for the Nexus, according to Shimano's German distributors, is 50,000km. Mean time between failures for the Rohloff is -- unknown. The last time I looked, several years ago, there were known Rohloffs with 160K kilometers/100K miles on them. The number of breakages, even counting the ones that pointed to obvious abuse, were statistically insignificant, the number of total irrecoverable failures were nil. At that point I decided it was an answered question: my Rohloff will see me out. It would be a waste of money, even here in the wilds of West Cork, to buy a spare Rohloff wheel against the day my Rohloff wheel had to go to Germany.

By the way, if you haven't caught up to this fact yet: every few years Rohloff talks about a lighter, nimbler model, and then just quietly disappears it, clearly because they consider that the inevitably higher rate of breakages will damage their reputation for rock solid engineering. There's always enthusiasm for the lightweight model among the old road racers who grew up in a weight weenie cycling culture, but I won't buy one. I'm an old Porsche driver: I like the most solid German engineering. I reckon that for the quality of engineering and its longevity the Rohloff box is just the perfect weight.

Also, it might interest you to know that the Rohloff was designed as a German agricultural implement for mud plugging cyclists (Bernd Rohloff's own sport), without a thought for tourists. It was just happenstance that Utopia-velo, who don't march to anyone else's drummer and was looking for a stronger box than the Nexus, picked it up for touring bikes, and later the strong-minded parties at Thorn discovered it fitted their concept of their touring bikes well. The rest of the tourist niche manufacturers picked up the Rohloff because they saw two aspirational bike makers doing so, sometimes not quite understanding why Utopia and Thorn had chosen it.


Andre Jute

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Re: Thorn Mercury 650b owner review
« Reply #34 on: August 15, 2021, 12:10:33 PM »
For the longterm record that Moronic is creating here, I've taken this statement up at http://thorncyclesforum.co.uk/index.php?topic=14325.msg106915#msg106915

Perhaps the Rohloff hub is slightly less efficient than a derailleur system in optimum condition, but for how long does that condition continue unless the rider is a fanatic who diligently cleans the drivetrain after each ride?

PH

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Re: Thorn Mercury 650b owner review
« Reply #35 on: August 15, 2021, 07:34:33 PM »
Reynolds 631 is not heat treated.
Indeed, heat treated 631 becomes 853.

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #36 on: August 17, 2021, 08:54:04 AM »
Well I sent my compliments to Thorn, thanking them for supplying such a great bike and then enquitpring of the material in the fork blades.

Got a reply from Robin, painstakingly responding to each of my compliments and then telling me that a document specifying the grade of steel used in the fork would be in the building somewhere but he was too busy to chase it down.  ;D

It occurred to me that as peculiar as Thorn's methods of promotion might seem, they work.

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #37 on: August 18, 2021, 07:38:32 AM »
At the risk of triggering a long discussion on lighting, I'll comment briefly on the SON dynamo and Edelux II headlamp Thorn offers for the Mercury and other models as an accessory.

I hemmed and hawed over this, and eventually went for it. The argument against is that battery lights do a good job these days. And unless you're commuting on the bike or running Audax events, you might not often need lights.

Having fitted hub lighting, I have found it's extended my riding in a way that battery lights likely would not have (for me). If the opportunity is there for a late evening ride, I will take it. And I can embark late on long day rides secure in the belief that I'll have lights to get home with.

With a frequency that has surprised me, I also set off for fitness rides of an hour or so after dark.

None of these opportunities would have been unavailable if I had instead purchased a battery system. However, I doubt I'd have used the battery system  in the same way, and I doubt I'd have developed a reliable charging routine.

I find drag from the hub imperceptible - with the light set to auto, where it switches on automatically even in persistent shadow in daytime, I have no idea whether the light is on or off.

The beam thrown is astonishingly useful. On the narrow local bike paths, it throws an illuminated tunnel down the road 100 metres or more, lighting the vegetation on both sides as well to about shoulder height. I'm quite comfortable that I can see what I need to.
« Last Edit: August 18, 2021, 07:41:20 AM by Moronic »

Matt2matt2002

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Re: Thorn Mercury 650b owner review
« Reply #38 on: August 18, 2021, 10:43:06 AM »
I have a Son dynamo on my Raven Tour.

Did I pick you up correctly? If the light is on, there is ( slightly) more drag?

I had thought the dynamo was ' working' all the time.

Asking as one who doesn't know Watt from an Amp.
Never drink and drive. You may hit a bump  and spill your drink

PH

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Re: Thorn Mercury 650b owner review
« Reply #39 on: August 18, 2021, 11:26:56 AM »
Did I pick you up correctly? If the light is on, there is ( slightly) more drag?
Yes, there's no free lunch (Or light*) it's been thoroughly tested and this thread gives a link and some detail:
http://thorncyclesforum.co.uk/index.php?topic=14185.0

Can you notice the difference? I can't, I frequently get home and realise I've ridden all day with the lights on, then imagine how much faster I'd have been with them off...

*An early Shimano model had more drag with the lights off, but that was down to poor circuitry and they soon corrected it.

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #40 on: August 18, 2021, 12:27:40 PM »
I have a Son dynamo on my Raven Tour.

Did I pick you up correctly? If the light is on, there is ( slightly) more drag?

I had thought the dynamo was ' working' all the time.

Asking as one who doesn't know Watt from an Amp.

And you've made the point beautifully. Compared with light off, the hub is much more draggy with the light on. But even "much more" is so little that you had assumed it made no difference.

Andre Jute

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Re: Thorn Mercury 650b owner review
« Reply #41 on: August 18, 2021, 01:40:45 PM »
Old but still relevant dynamo test at
http://www.myra-simon.com/bike/dynotest.html
contains the ur-discussion of generator drag, and converts it into a road slope.

Anyway, since the lifespan of the LEDs in modern lamps is 50K hours, there's no reason not to run bicycle lamps 24/7, including as daylight running lamps. Mine are never switched off.

tyreon

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Re: Thorn Mercury 650b owner review
« Reply #42 on: August 30, 2021, 09:01:05 AM »
What an excellent review,Moronic.

Bikes looks fantastic

I think I could just sit down in wonder and look at it for 3 cuppas(a good 90 minutes)

I think I would have been overwhelmed when getting it. By your writing you seem a more measured man than myself who would have rushed to assemble it,then made some hash of things.

Your review and memory of past machines and experiences I question. I only do so because I am never sure. I know lots on here can say about cycling qualities and handling issues. But unless a bike is over exaggerated in set up I tend to forget which one I prefer. Then,I have to ride a bike for,say,a time before I get to know it...then like or dislike it. Setting up a saddle for me is a day's job,with lots of minor alterations and wotnot. This can go on for 5 days or so: boring,and annoying.

Shish! You have the bees knees there. Please give my regards to Wycheproof: the town where time can stand still,and so you somehow have more of it.

Luverly bike. Good write up. Happy travels. Hope some normality return soon.

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #43 on: August 31, 2021, 09:52:42 AM »
I'm happy you enjoyed the read, tyreon, and thanks for the compliments on the bike.

Yes I'm almost shocked over how much I enjoy the look. Before it arrived, I had just about resigned myself to celebrating the function and ignoring the form.

As for the three cuppas - I'm with you on that, even if I've never quite got to three.

It's understandable you'd question my recollections of how past bikes behaved. Let's just say they're "true for me" - as in, I'm not consciously fabricating. Same with the comments on handling etc really. The point of my recording the former was to provide some context for how confidently readers could accept the latter.

I think it might be a few decades since I last passed through Wicheproof. IIRC it was in the local news this week as the local government area with the highest proportion of residents vaccinated against the plague.

Moronic

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Re: Thorn Mercury 650b owner review
« Reply #44 on: September 02, 2021, 02:21:33 PM »
I've realised that in responding to tyreon's comments there's a bit I could add for context.

In a previous life I made a lving from reviewing the performance of recently released motorcycles, and so I'm in the habit of analysing the handling and general responsiveness of single-track vehicles.

My experience of various bicycles is broad but thin. So I'm no expert there. OTOH I have likes and dislikes that aren't wholly ignorant.